Assertion without empirical basis : an econometric appraisal of monetary trends in ... the United Kingdom, by Milton Friedman and Anna J. Schwartz

This paper critically re-evaluates some of the fundamental empirical claims about monetary behavior in the United Kingdom made by Milton Friedman and Anna J. Schwartz in their 1982 book Monetary Trends in the United States and the United Kingdom. We focus on six aspects of their analysis: the exogeneity of money; their claims of the constancy and correct specification of their money-demand equation; their interpretation of a dummy variable in that equation as capturing a \"shift in liquidity preference\" for 1921-55; their treatment of the interdependence of money, income, prices, and interest rates; and their use of phase-average data. They fail to support many of their empirical assertions with valid econometric evidence: in particular, they leave untested many conditions necessary to sustain their inferences. However, those conditions either are in part directly testable from their data or have testable implications: we test many of those hypotheses and reject virtually all of them. We reject basic claims made for their empirical model of money demand, e.g., those of parameter constancy, price homogeneity, and normality of the disturbances. En route, we show that their model of velocity as a constant performs poorly relative to the \"will-o'-the-wisp\" model of velocity as a random walk. As constructive evidence against their models, we develop a money-demand model superior to either model of velocity, and which has an unexplained residual variance less than one tenth that of their money-demand equation. This paper, however, is not an \"anti-monetarist\" critique; rather, it is a pro-econometrics tract which highlights the practical dangers of seeking to analyze complex stochastic processes while eschewing modern econometric methods.